Used in the field of industrial automation process control to the medium flow rate, pressure, temperature, liquid level, etc. The adjustment of process parameters, according to the control signals of the automatic system, automatically adjust the opening of the valve, so as to realize the medium flow rate, pressure, temperature and liquid level adjustment, the body type selection is an important part in the choice of the valve body,
Type a lot of the valve body, the commonly used single seat, seat, double Angle, diaphragm, small flow rate, tee, eccentric rotating, butterfly valve, the sleeve, ball valve and other 10 kinds of,
Before selecting the valve, to control the process of medium, a careful analysis of process conditions and parameters, collect enough data, understand the system requirement for regulating valve, and according to the data collected by sure you want to use the valve type,
In the choice of specific, consider the following aspects:
(1) the shape and structure of the valve core mainly according to the selected flow characteristic and unbalanced force and other factors to consider,
(2) corrosion resistance due to the corrosive medium, in the case of can satisfy regulating function, try to choose structure simple valves,
(3) to wear when fluid medium is suspending liquid containing high concentrations of wear particles, the valve core and valve seat interface serious friction and shut down every time, and as a result, the valve port should be smooth and materials within the valve should be stiff,
(4) to prevent flash and cavitation, flashing, cavitation in liquid medium, in the process of practical production, flash and cavitation phenomenon not only affects the calculation of flow coefficient, still can form the vibration and noise, shorten the service life of the valve, therefore, should choose to prevent flash and cavitation of the valve,
(5) medium temperature and pressure when the medium with high temperature and pressure change is big, the valve core and valve seat material should vary according to the temperature and pressure of the small valve to select,